This invention relates to a computer system and, more specifically, a technique of controlling file caches in a computer system that includes a network attached storage system (NAS).
There has been proposed a computer system with NAS (Network Attached Storage), a storage system that is hooked up to a network and connected to plural servers via the network, thus enabling the servers to share files. In this type of computer system, a cache memory is provided in the network to speed up access to disks.
A technique related to such a network cache memory has been disclosed in JP 2002-91825 A, for example. According to this technique, when a file requested from a terminal is not found in a file storing portion of the cache memory, the requested file is obtained from a server and stored in the file storing portion if there is a space in the file storing portion and, if there is no space available, files are deleted from the file storing portion in the reverse order of priority and in reverse chronological order of last referred time to make room for the file obtained from the server.